Many printers have a power supply. The amount of power draw required by a printer depends on a number of factors such as the density of the image being printed (for example, a 3-line email requires less energy to print than a full page color photograph), the quality of the printing process (higher resolution versus lower resolution), and other factors. A power supply for a given printer has a specific rating (e.g., 180 watts) that defines the upper limit of its power delivery capacity. Each power supply has weight, occupies a volume, and generates heat, all of which may be problematic for a printer design.